Then liberation came; again the summer was very complicated, I will not go into detail. My nominal activity was to raise horses, which of course I didn't know how to do, but my real activity was something else. I would like to skip that. Perhaps I will tell one story about that because it's somewhat unusual. I landed for reasons too long to explain in a little chateau, a big farm that was raising horses, what they call half-bred horses or they call them Anglo-Norman half-breeds. They're English racehorses crossed with other horses to provide the kind of animals for the colonels and generals in the cavalry. Very beautiful horses but short of thoroughbred and able to do some work. Well, the first day I arrived the owner of the place invited me for lunch, and said, "Well, in 1913 my horse Phoebus won the derby in Lyon. "Hi dam was.. his sire was.." and he recited to me the pedigree of the horse to many generations. In the evening Monsieur de Riviere, as his name was, started again ... "In 1913 -" I stopped him. "Your horse Phoebus won the derby in Lyon. His -" and I recited the pedigree absolutely as verbatim. I was able to do that routinely. I didn't try to remember the pedigree of that horse, but I remembered it, and that saved my life because Monsieur de Riviere was so impressed that anybody had listened to him. He was used not to be listened to and being spurned as an old cavalry man whom everybody viewed as being a man of the past and not worth listening to. Some people have saved their life because they could tell one thousand and one tales of Scheherazade. I saved my life, to some extent, by reciting the pedigree of a horse long dead. It was actually rather interesting to raise these horses and to be in this community of people who were then at the end - they were raising horses by force of habit. Nobody wanted their horses as there was no need for the horses, but later on, of course, when France and England became more prosperous, horses came back. At that time they were just animals that those people had been paid in the past to ride and to raise and to breed.

Benoît Mandelbrot (1924-2010) discovered his ability to think about mathematics in images while working with the French Resistance during the Second World War, and is famous for his work on fractal geometry - the maths of the shapes found in nature.

Daniel Zajdenweber is a Professor at the College of Economics, University of Paris.

Bernard Sapoval is Research Director at C.N.R.S. Since 1983 his work has focused on the physics of fractals and irregular systems and structures and properties in general. The main themes are the fractal structure of diffusion fronts, the concept of percolation in a gradient, random walks in a probability gradient as a method to calculate the threshold of percolation in two dimensions, the concept of intercalation and invasion noise, observed, for example, in the absorbance of a liquid in a porous substance, prediction of the fractal dimension of certain corrosion figures, the possibility of increasing sharpness in fuzzy images by a numerical analysis using the concept of percolation in a gradient, calculation of the way a fractal model will respond to external stimulus and the correspondence between the electrochemical response of an irregular electrode and the absorbance of a membrane of the same geometry.